An LED light-emitting device mainly comprises a combination of a phosphor and an LED chip serving as an excitation light source, and can realize various colors of emission light according to the combination.
Specifically, a white LED light-emitting device, which radiates white emission light, comprises a phosphor in combination with an LED chip that emits light in the blue region. For example, the device comprises a phosphor mixture and an LED chip giving off blue light. In practice, a phosphor emitting yellow light, which is complementary to blue light, is often adopted as the phosphor to produce a pseudo-white LED light-emitting device. Further, a three-wavelength white LED device is also developed which comprises a LED chip emitting blue light, a green- or yellow-light emitting phosphor and a red-light emitting phosphor. As an example of the red-light emitting phosphor used in that light-emitting device, K2SiF6:Mn phosphor is known.